Material discharge apparatus

ABSTRACT

An apparatus for discharging a flowable material from a container having a discharge duct comprises support means for supporting the container, preferably in the form of a conical hopper having a central aperture, a clamping enclosure extending downwardly from the hopper, a discharge duct having its mouth located inside the enclosure and facing upwardly towards the aperture in the hopper, and an annular clamping ring inside the enclosure, the ring being movable so as to clamp the spout of the container against the mouth of the discharge duct. Preferably, the enclosure is substantially sealed, with reclosable access openings provided in a front wall of the enclosure through which the spout of the container can be manually handled. The enclosure is also provided with vacuum means to create a negative pressure in the enclosure and therefore prevent release of the contents of the container into the atmosphere.

FIELD OF THE INVENTION

[0001] The present invention relates to material handling equipment, andmore particularly to an apparatus for discharging a powdered materialfrom a flexible intermediate bulk container.

BACKGROUND OF THE INVENTION

[0002] Flexible intermediate bulk containers, also known as “bulk bags”,typically comprise an outer bag and an inner liner having a tubularspout. Such containers are used for the transfer of a wide range ofsolid materials including foodstuffs and pharmaceuticals, which must beprotected from contamination. The outer bag can be used many times byinserting a replacement liner each time the bag is used. The linerprevents contamination of the product inside the bag and provides somemeasure of protection to the contents should the outer bag becomedamaged. The tubular spout of the inner liner is normally completelyenclosed in the outer bag and is exposed prior to discharge of thematerial by folding back a flap in the outer bag and pulling the spoutout of the outer bag.

[0003] A typical apparatus and method for discharging powdered materialsfrom a flexible intermediate bulk container are described in U.S. Pat.No. 4,946,071 to Poulton, issued on Aug. 7, 1990. As illustrated inFIGS. 2 and 3 of Poulton, a container is delivered to the vicinity ofthe discharge apparatus on a pallet, and is then suspended by loops froma rigging frame and lifted by a fork-lift truck, at which point a flapon the outer bag is pulled aside to expose the spout. The flexibleintermediate bulk container is then lowered onto a conical hopper suchthat the spout projects downwardly through a central hole in the hopper.The spout is then untied and pulled down to engage an upturned cuff overthe mouth of a discharged duct. As shown in FIGS. 4 and 5 of the Poultonpatent, a clamping ring is then lowered downwardly to clamp the spout ofthe inner liner against the mouth of the discharge duct. Discharge isthen effected.

[0004] The use of the Poulton apparatus prevents contamination ofcontents of the container and release of the contents into theatmosphere during discharge of the container. However, the Poultonapparatus has the disadvantage that, during engagement and disengagementof the spout with the discharge duct, some amount of material isinevitably released into the atmosphere, resulting in contamination ofthe air in the vicinity of the apparatus and possibly resulting incontamination of the contents of the container. Poulton has theadditional disadvantage that the distances between the hopper, theclamping ring and the discharge duct are such that the Poulton devicecan only be used with containers having very long spouts, typicallyabout 36 to 40 inches. This is much longer than the standard spoutlength of 17 to 20 inches used in most flexible intermediate bulkcontainers.

[0005] Therefore, there is a need for a improved material dischargingapparatus which overcomes these problems.

SUMMARY OF THE INVENTION

[0006] The present invention overcomes the above-mentioned disadvantagesby providing a discharge apparatus in which a substantially sealedenclosure is provided below a hopper on which a flexible intermediatebulk container is supported.

[0007] In the apparatus of the invention, the lower end of the hopperextends into an upper region of the sealed enclosure, such that theaperture in the hopper is spaced above the mouth of a discharge duct,which extends upwardly into the sealed enclosure. The enclosure alsocontains a clamping ring which clamps the spout of the inner bag againstthe mouth of the discharge duct.

[0008] In the apparatus of the invention, the spout is manually pulleddown over the mouth of the discharge duct through one or more reclosableaccess openings in the enclosure. The clamping rings then lowered toclamp the bag spout against the mouth of the discharge duct. Preferably,the enclosure is under a negative pressure so that release of materialinto the atmosphere during handling of the spout and discharge of thematerial is effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The invention will now be described, by way of example only, withreference to the following drawings, in which:

[0010]FIG. 1 is a front elevational view of a portion of a dischargeapparatus according to the present invention, showing the preferredclamping enclosure;

[0011]FIG. 2 is a cross-sectional view of the clamping enclosure of FIG.1, after the spout of the bag liner has been drawn over the mouth of thedischarge duct;

[0012]FIG. 3 is a cross-sectional view of the clamping enclosure of FIG.1, illustrating clamping of the bag spout between the clamping ring andthe mouth of the discharge duct; and

[0013]FIG. 4 is a close up view of area A in FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0014] A preferred embodiment of the invention will now be describedwith reference to FIGS. 1 to 4.

[0015]FIG. 1 illustrates a front elevational view of a portion of apreferred apparatus 10. It will be appreciated that components ofapparatus 10 which are not shown in the drawings are conventional andare similar to those shown in the above-mentioned Poulton patent, whichis hereby incorporated by reference in its entirety.

[0016]FIG. 1 illustrates a flexible intermediate bulk container 12 whichis preferably suspended from a hoist by loops as shown in the Poultonpatent. As illustrated in FIGS. 2 and 3, the flexible intermediate bulkcontainer 12 comprises an outer bag 13 and an inner liner 15 with adischarge spout 17. Access to the spout 17 is provided by folding back aflap 11 provided in the outer bag 13.

[0017] The flexible intermediate bulk container 12 is at least partiallysupported by hopper 14, which comprises support walls 18 surrounding anaperture 20 (shown in FIG. 2) sized to receive discharge spout 17.Preferably, the hopper 14 has a truncated conical shape, with thesupport walls 18 radiating outwardly and upwardly from the aperture 20.Preferably aperture 20 is substantially centrally located in a lower endof the hopper 14. In one particularly preferred embodiment, the supportwalls 18 of hopper 14 are inclined at an angle of about 30 to 40° to thehorizontal, more preferably about 35°.

[0018] Preferably, the hopper is supported atop vertical support members16 which preferably extend downwardly to the floor of a work area.

[0019] As illustrated in FIG. 2, the lower end of hopper 14 extendsdownwardly through an upper wall 24 of a clamping enclosure 22. As shownin the drawings, clamping enclosure 22 also comprises a front wall 26, apair of side walls 28, a rear wall 30 and a bottom wall 32. The clampingenclosure 22 is substantially sealed with the exception that it is opento the aperture 20 of hopper 14. During use of the apparatus 10, theaperture 20 is effectively sealed by container 12.

[0020] The front wall of clamping enclosure 22 is provided with at leastone reclosable access opening, preferably two openings 34 as illustratedin FIG. 1. Each access opening 34 is substantially rectangular, beingcovered by a resilient membrane, such as rubber, the membrane 36 havinga slit 38 extending vertically along substantially its entire height.The slit is provided to allow access for an operator to manuallymanipulate the spout of the bulk container inside the enclosure 22.Preferably, the front wall 26 of enclosure 22 is comprised of atransparent material such as poly(methyl methacrylate) to allow theoperator to visually confirm proper positioning of the discharge spout17 inside enclosure 22.

[0021] A discharge duct 40 extends vertically upwardly through bottomwall 32 of clamping enclosure 22 such that the open mouth 42 of duct 40is contained inside enclosure 22. The mouth 42 mouth which facesupwardly toward the aperture 20 and is spaced below aperture 20 by adistance sufficient to allow the discharge spout 17 to be pulled downover the mouth 42 of the discharge duct 40 in the manner shown in FIG.2. Preferably, the discharge duct 40 is provided at its mouth 42 with acylindrical, horizontal upper face 44.

[0022] Also enclosed within clamping enclosure 22 is an annular clampingring 46 having an inner diameter which is sized to receive the dischargespout 17 of the container 12 and an outside diameter sized to clamp theopen mouth 42 of the discharge duct 40. The annular clamping ring 46 ismovable between an upper position shown in FIG. 2 and a lower positionshown in FIGS. 3 and 4. In the upper position, the ring 46 is spacedabove the open mouth 42 of the discharge duct. In its lower position, aclamping surface 48 of clamping ring 46 clamps the discharge spout 17against the upper face 44 of the discharge duct 40.

[0023] Preferably, the clamping surface 48 of annular clamping ring 46is provided with resilient sealing means to sealingly clamp the spout ofthe bag against the upper face 44 of discharge duct 40. Preferably, inthe embodiment shown in the drawings, the resilient sealing meanscomprises a rubber O-ring 49 which is received in a groove 51 in theclamping surface 48 of clamping ring 46.

[0024] The apparatus 10 also provides means for moving the clamping ring46 between its upper and lower positions. Preferably, as illustrated inthe drawings, the means for moving the clamping ring 46 comprises a pairof hydraulic cylinders 50 located outside and adjacent to enclosure 22.Each hydraulic cylinder 50 is connected to the clamping ring 46 by ahorizontal linkage 52 having one end connected to a cylinder 50 and anopposite end connected to clamping ring 46 through side wall 28. In aparticularly preferred embodiment, the clamping ring 46 and the linkages52 are integrally formed. In order to accommodate the vertical movementof the clamping ring 46 and linkages 52, the side walls 28 of enclosure22 are preferably provided with elongate openings 53 having resilientsealing means (not shown) to prevent the release of material from theenclosure 22.

[0025] The apparatus 10 is also provided with vacuum means to create anegative pressure inside the enclosure 22, thereby substantiallypreventing release of material into the atmosphere from inside theenclosure 22. The vacuum means preferably comprises a vacuum device (notshown) which applies suction to the enclosure 22 through an exhaust port54 provided in the rear wall 30 of the enclosure 22. Preferably, a shownin the drawings, a horizontal plane in which the mouth 42 of thedischarge duct 40 is also located also passes through the exhaust port54, so that the exhaust port 54 is in close proximity to the mouth 42 ofduct 40 and the end of discharge spout 17, where most material would bereleased during handling of the spout 17. Preferably, the horizontalplane passes substantially centrally through the exhaust port 54.

[0026] It will be appreciated that the apparatus 10 of the presentinvention also includes a number of other conventional components whichhave not been shown in the drawings. For example, the apparatus 10 alsocomprises a hoist by which the container 12 can be raised and loweredrelative to hopper 14.

[0027] The operation of the apparatus 10 will now be described below.

[0028] Firstly, the flexible intermediate bulk container 12 istransported to the vicinity of the apparatus 10 on a pallet as shown inFIG. 2 of the Poulton patent. The container is then lifted as in FIG. 3of the Poulton patent and the flap 11 of the outer bag 13 is pulled backto reveal the spout 17 of the inner liner 15. The container 12 is thentransferred to a hoist and is lowered onto the hopper 14 so that thespout 17 extends downwardly through aperture 20. An operator thenextends his or her hands through the reclosable openings 34 to pull thespout 17 down over the open mouth 42 of discharge duct 40. The operatorthen removes his or hand from the opening 34 and the clamping ring 46 islowered by hydraulic cylinders 50 until the spout of the bag is securelyclamped between the clamping surface 48 of clamping ring 46 and theupper face 44 of discharge duct 40. This is shown in the close up viewof FIG. 4. After discharge of the material is complete, the hydrauliccylinders are operated to raise the clamping ring from the mouth 42 ofdischarge duct 40. The operator then ties the spout of the bag and it isremoved from the hopper 14. During the entire time that container 12 issupported on hopper 14, the vacuum means is operated to prevent releaseof material from the enclosure.

[0029] Although the preferred embodiments of the invention have beendescribed in conjunction with a flexible intermediate bulk containershown in the Poulton patent having a flap which must be pulled aside toreveal spout, the invention can be used with other types of containershaving spouts, including most conventional flexible intermediate bulkcontainers having standard length spouts.

[0030] Although the invention has been described in connection withcertain preferred embodiments, it is not to be limited thereto. Rather,the invention includes all embodiments which may fall within the scopeof the following claims.

What is claimed is:
 1. An apparatus for discharging a flowable materialfrom a container having a discharge spout, comprising: (a) support meansfor supporting said container, said support means comprising supportwalls surrounding an aperture sized to receive the discharge spout ofthe container; (b) a substantially sealed clamping enclosure extendingdownwardly from, and sealingly fixed to, said support means, saidenclosure having a front wall, side walls a bottom wall and an upper endwhich is open to said aperture, said front wall provided with at leastone reclosable access opening allowing manipulation of said dischargespout inside the enclosure; (c) a discharge duct having an open mouthlocated inside said enclosure and facing upwardly toward said aperture,said mouth of said discharge duct being spaced below said aperture by adistance sufficient to allow the discharge spout of the container extendover the mouth; (d) an annular clamping ring inside said enclosure, saidannular clamping ring having an inner diameter sized to receive thedischarge spout of the container and an outside diameter sized to clampthe open mouth of the discharge duct, the annular clamping ring beingmovable between an upper position at which the ring is spaced above theopen mouth of the discharge duct and a lower position at which the ringengages the open mouth of the discharge duct; (e) moving means to movesaid clamping ring between the upper and lower positions; and (f) vacuummeans to create a negative pressure inside said enclosure, therebysubstantially preventing release of said material into the atmospherefrom inside said enclosure.
 2. The apparatus of claim 1 , wherein saidsupport means is of a truncated conical shape, with said support wallsradiating outwardly and upwardly from said aperture which issubstantially centrally located in a lower end of said support means. 3.The apparatus of claim 2 , wherein said support walls are inclined at anangle of about 30 to 40 degrees to the horizontal.
 4. The apparatus ofclaim 1 , wherein the enclosure additionally comprises a rear wallopposite said front wall, and wherein said vacuum means comprises anexhaust port in the rear wall, and a vacuum device which applies suctionto the enclosure through said exhaust port.
 5. The apparatus of claim 1, wherein said mouth of said discharge duct is located in a horizontalplane which passes through said exhaust port.
 6. The apparatus of claim5 , wherein the horizontal plane passes substantially centrally throughthe exhaust port.
 7. The apparatus of claim 1 , wherein the dischargeduct is provided at its mouth with a cylindrical, horizontal upper facewhich is engaged by said annular clamping ring during clamping.
 8. Theapparatus of claim 1 , wherein the annular clamping ring has a lowerclamping face provided with resilient sealing means for sealinglyclamping the discharge spout of the container against the upper face ofthe discharge duct.
 9. The apparatus of claim 1 , wherein the front wallof the enclosure is provided with two of said access openings, theopenings being located to either side of a vertical axis passingcentrally through said aperture and the mouth of the discharge duct. 10.The apparatus of claim 9 , wherein each of said access openings isclosed by a resilient membrane, said membrane having a slit allowingaccess through the access opening.
 11. The apparatus of claim 1 ,wherein said moving means comprises a pair of hydraulic cylinderslocated outside the enclosure and linkages connecting said hydrauliccylinders to said annular clamping ring.
 12. The apparatus of claim 11 ,wherein each of said linkages passes through an opening in a side wallof the enclosure between its associated hydraulic cylinder and theannular clamping ring, the openings in the side walls being elongate andhaving sealing means to prevent release of the material.